THIRTY DAY MORTALITY AND RELATED VARIABLES IN OPEN HEART PATIENTS AT THE KENYAT'TA NATIONAL HOSPITAL, NAIROBI

Abstract

Objective: To determine the thirty-day mortality of open-heart patients at the Kenyatta
National Hospital in Nairobi from June 1973 to October 2000 and; to look at likely variables
related to mortality.
Design: A retrospective analysis of data from the unit database. Data on this database were
collected prospectively from September 1997 to the time of study. Data in respect of the
period prior lto this were collected retrospectively from patient files, ward and theatre
records.
Setting: Kenyatta National Hospital (KNH), Nairobi.
Patients: A total of 563 open-heart patients operated at the KNH were included in the study.
Results: The thirty-day mortality rate calculated at 17.4% for the study period compared to
a hospital mortality rate of 16.9 %.Surgical repair for complex congenital pathology, surgery
on patients with, a left atrial (LA) dimension or a left ventricular end systolic dimension
(LVESD) greater than 5 cm orland a cross clamp time greater than 60 minutes all had a
significantly g,reater risk of mortality on bivariate analysis. This is compared to surgery for
simple hole in the heart, LA and LVESD dimensions less than 5cm and cross clamp times less
than 60 minutes (pc0.05). The increased risk of mortality with these variables was 3.33,3.95,
3.18 and 1.8 times greater than their counterparts, respectively. For patients having surgery
for an acquired pathology, only a cross clamp time greater than 60 minutes and a left atrial
size greater than 5cm were independent risk factors for thirty day mortality using logistic
regression an:alysis. For patients having surgery for correction of a congenital defect, only a
cross clamp time of more than 60 minutes was an independent predictor of mortality
(p < 0.05).
Conclusions: The higher mortality rate is amongst others, probably related to the late
presentation of our patients for surgery when their myocardial function is below the
optimum for surgery. There is a need to bring down the mortality through more stringent
patient selection, preoperative preparation and reduction of surgical ischaenlic times,
however without depriving the patients in need of surgery.